Treg and immunosuppression The Treg study collected samples during the malaria transmission season. Over the malaria transmission season from June 2011 until December 2011, we enrolled 967 acute episodes of P. falciparum malaria, from which samples were obtained. The day 21 follow up visits were completed end of January 2012. All planned assays for the study have been completed. In addition, qPCR was performed from Day 21 samples to ascertain that the subjects had cleared parasites after receiving treatment. The number of severe malaria cases was low and thus the power to detect differences in Treg levels with subjects who had an uncomplicated malaria case was low. There were no significant differences between Treg levels in severe malaria cases compared to uncomplicated cases in their prior episode. We have expanded the scope of the project to include measuring markers of immune exhaustion/T cell suppression, along with Treg levels, to determine any association with immune function and vaccine responses. These studies will be performed in adults and children in cohorts at our study sites (Ouelessebougou; Bancoumana; Doneguebougou). The first cohort study has been launched in Ouelessebougou to compare children who receive Seasonal Malaria Chemoprevention with those who do not receive, for levels of T regs as well as markers of T cell suppression. The second cohort will be launched in Bancoumana later this quarter, to examine whether antimalarial treatments of adults prior to vaccination with a meningococcal vaccine will enhance anibody responses. To prepare for these cohorts and future cohorts under this project, flow cytometry methods for measuring T regs and markers of T cell suppression have been transferred to ICER labs in Mali. These assays are currently ongoing.